USE database1
GO
SET IDENTITY_INSERT dbo.MobileDevice ON
INSERT INTO dbo.MobileDevice (MobileDeviceID, UserAgent, Name)
SELECT * from database2.dbo.MobileDevice
SET IDENTITY_INSERT dbo.MobileDevice OFF

If the databases are in different servers you need to setup a linked server connection between them and then use query like

USE database1
GO
SET IDENTITY_INSERT dbo.MobileDevice ON
INSERT INTO dbo.MobileDevice (MobileDeviceID, UserAgent, Name)
SELECT * from Server2.database2.dbo.MobileDevice
SET IDENTITY_INSERT dbo.MobileDevice OFF